Numerical analysis of latent heat thermal energy storage using encapsulated phase change material for solar thermal power plant
Numerical analysis of latent heat thermal energy storage using encapsulated phase change material for solar thermal power plant
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DOI：
10.1016/j.renene.2016.04.018
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发表时间：
2016-09-01
期刊：
影响因子：
8.7
通讯作者：
Saha, Sandip K.
中科院分区：
文献类型：
--
作者：
Bhagat, Kunal;Saha, Sandip K.
热能储存通过减少太阳辐射固有的波动和不稳定性来提高太阳能热发电厂的负载稳定性和效率。本文对填充床潜热储能系统在充放热过程中消除传热流体温度波动的瞬态响应进行了数值研究。由球形封装相变材料（PCM）组成的填充床被集成在基于有机朗肯循环的太阳能热电厂中用于发电。本文建立了一个综合的数值模型，该模型采用导热系数的流动方程和双温非平衡能量方程进行传热，并结合焓法来考虑相变材料的相变。进行系统的参数研究，以了解质量流率，入口充电系统，存储系统的尺寸和封装的壳直径上的存储系统的动态行为的效果。计算了不同几何参数和运行参数下循环中HTF的总效率和瞬态温差，以评估系统性能。研究发现，提高质量流量和入口充能温度可以显著提高潜热储能系统的储能和释能能力。通过减小孔隙率可以有效地减小HTF温度的瞬态变化。(C)2016爱思唯尔有限公司版权所有
Thermal energy storage improves the load stability and efficiency of solar thermal power plants by reducing fluctuations and intermittency inherent to solar radiation. This paper presents a numerical study on the transient response of packed bed latent heat thermal energy storage system in removing fluctuations in the heat transfer fluid (HTF) temperature during the charging and discharging period. The packed bed consisting of spherical shaped encapsulated phase change materials (PCMs) is integrated in an organic Rankine cycle-based solar thermal power plant for electricity generation. A comprehensive numerical model is developed using flow equations for HTF and two-temperature non-equilibrium energy equation for heat transfer, coupled with enthalpy method to account for phase change in PCM. Systematic parametric studies are performed to understand the effect of mass flow rate, inlet charging system, storage system dimension and encapsulation of the shell diameter on the dynamic behaviour of the storage system. The overall effectiveness and transient temperature difference in HTF temperature in a cycle are computed for different geometrical and operational parameters to evaluate the system performance. It is found that the ability of the latent heat thermal energy storage system to store and release energy is significantly improved by increasing mass flow rate and inlet charging temperature. The transient variation in the HTF temperature can be effectively reduced by decreasing porosity. (C) 2016 Elsevier Ltd. All rights reserved.